Inpatient Mortality Among Solid Organ Transplant Recipients Hospitalized for Sepsis and Severe Sepsis

Severe community-acquired pneumonia in immunosuppressed patients admitted to the ICU

BACKGROUND

Immunocompromised patients with severe Community-Acquired Pneumonia (sCAP) poses higher risk for poor prognosis. This study details the clinical characteristics and factors linked to immunosuppression and mortality both acutely and long-term.

METHODS

This analysis of the MIMIC-IV database included ICU adult patients with CAP diagnosis categorized by the presence or absence of immunosuppression. Univariable and multivariable analyses determined factors related to immunosuppression and in-hospital, 6-and 12-month mortality post-admission. An adjusted survival analysis assessed the impact of immunosuppression on mortality.

RESULTS

A total of 4742 patients were included, with 1520/4742 (32 %) immunocompromised with a mean age (SD) of 64 (14.7) years, and 896/1520 (58.9 %) males. Solid malignancy was the most frequent immunosuppression cause (797/1520; 52.4 %). The most frequent comorbidities were chronic pulmonary disease (585/1520; 38.5 %) and congestive heart failure (411/1520; 27 %). Immunocompromise was associated with P. jirovecii (0.3 % vs. 1.1 %; p < 0.01) and Aspergillus (1.2 % vs 3.1 %; p 0.03) infection and increased hospital (IH) and solid malignancy (IH: OR 1.98 [95 % CI 1.55-2.52]; 6 M: OR 2.43 [95 % CI: 1.92-3.08]; 12 M: OR: 0.72 [95 % CI 0.47-1.11]; p = 0.14) was consistently associated with mortality at in-hospital and 6M follow-up.

CONCLUSION

Immunocompromised patients with sCAP had higher acute and long-term mortality independent of the disease severity and were frequently infected with opportunistic microorganisms.

Carbapenem-resistant Enterobacterales in solid organ transplant recipients

Carbapenem-resistant Enterobacterales (CRE) are an important threat to the health of solid organ transplant recipients (SOTr); data comparing outcomes of SOTr with CRE to non-SOTr with CRE are lacking. A matched cohort study was performed within 2 prospective, multicenter, cohort studies (Consortium on Resistance Against Carbapenems in Klebsiella and other Enterobacterales and Consortium on Resistance Against Carbapenems in Klebsiella and other Enterobacterales 2). The epidemiology, desirability of outcome rankings outcomes, and mortality of SOTr and non-SOTr hospitalized in the United States (December 2011-August 2017) with clinical isolates with Centers for Disease Control and Prevention-defined CRE were compared. In total, 121 SOTr and 242 matched non-SOTr were included. Fifty-one percent of isolates met infection criteria. SOTr were younger (P < .001), less acutely ill (P = .029), less often had a malignancy history (P = .006), and more often were admitted from home (P < .001) than non-SOTr. SOTr had more favorable adjusted desirability of outcome rankings outcomes; a randomly selected SOTr had a 58% (95% confidence interval, 53%-64%) probability of a better outcome as compared to a randomly selected non-SOTr. All-cause 30-day mortality was 14% (17/121) in SOTr vs 25% (60/242) in non-SOTr, P = .018. After stabilized inverse probability weighted adjustment, SOTr had a 7% lower 30-day mortality risk than non-SOTr (95% confidence interval, -15% to 1%). SOTr with CRE do not have worse outcomes than matched patients without transplant history.

Intra-abdominal infection and sepsis in immunocompromised intensive care unit patients: Disease expression, microbial aetiology, and clinical outcomes

We compared epidemiology of intra-abdominal infection (IAI) between immunocompromised and non-immunocompromised ICU patients and identified risk factors for mortality. We performed a secondary analysis on the "AbSeS" database, a prospective, observational study with IAI patients from 309 ICUs in 42 countries. Immunocompromised status was defined as either neutropenia or prolonged corticosteroids use, chemotherapy or radiotherapy in the past year, bone marrow or solid organ transplantation, congenital immunodeficiency, or immunosuppressive drugs use. Mortality was defined as ICU mortality at any time or 28-day mortality for those discharged earlier. Associations with mortality were assessed by logistic regression. The cohort included 2589 patients of which 239 immunocompromised (9.2 %), most with secondary peritonitis. Among immunocompromised patients, biliary tract infections were less frequent, typhlitis more frequent, and IAIs were more frequently healthcare-associated or early-onset hospital-acquired compared with immunocompetent patients. No difference existed in grade of anatomical disruption, disease severity, organ failure, pathogens, and resistance patterns. Septic shock was significantly more frequent in the immunocompromised population. Mortality was similar in both groups (31.1% vs. 28.9 %; p = 0.468). Immunocompromise was not a risk factor for mortality (OR 0.98, 95 % CI 0.66-1.43). Independent risk factors for mortality among immunocompromised patients included septic shock at presentation (OR 6.64, 95 % CI 1.27-55.72), and unsuccessful source control with persistent inflammation (OR 5.48, 95 % CI 2.29-12.57). In immunocompromised ICU patients with IAI, short-term mortality was similar to immunocompetent patients, despite the former presented more frequently with septic shock, and septic shock and persistent inflammation after source control were independent risk factors for death.

Pneumonia in Transplant Recipients: A Comprehensive Review of Diagnosis and Management

Transplant recipients have an increased risk of complications, including graft dysfunction and infections, which can be life-threatening if not recognized early. Pneumonia ranks as one of the most frequent complications in both solid organ and hematopoietic stem cell transplants. Clinical symptoms manifest late during infections in immunocompromised patients. An aggressive approach centered on early confirmatory diagnosis and a low threshold for empiric therapy is often the most effective strategy. The isolation of a pathogen in an upper airway sample does not necessarily mean the same organism is responsible for pneumonia. Viruses such as CMV (cytomegalovirus virus) may function as co-pathogens for opportunistic infections in transplant recipients in addition to causing their own primary infectious syndrome. Furthermore, some viruses exhibit immunomodulatory effects that can affect the graft function. Given the exhaustive list of causative pathogens responsible for pneumonia, the best approach to the diagnosis is to have a conceptual framework that includes a detailed history, such as the type of transplant, degree of immunosuppression, antimicrobial prophylaxis, risk factors, time of presentation since transplantation and the radiographic pattern on the CT chest (computer tomography of the chest). Management depends predominantly on the degree of antimicrobial resistance, drug-to-drug interaction, and adjustments to the immunosuppression.

Multidrug-resistant organism bloodstream infections in solid organ transplant recipients and impact on mortality: a systematic review

Background

Bloodstream infections (BSIs) cause significant morbidity and mortality in solid organ transplant (SOT) recipients. There are few data regarding the contribution of MDR organisms (MDROs) to these infections. We evaluated the resistance percentage of MDRO BSIs in SOT recipients and the associated mortality.

Methods

A systematic review of MEDLINE and Embase databases up to January 2024, for studies of adult SOT recipients that quantified MDRO BSI resistance percentage and/or associated crude mortality. MDROs studied were carbapenem-resistant Enterobacterales (CRE), Acinetobacter baumannii (CRAB) and Pseudomonas aeruginosa (CRPA), third-generation cephalosporin-resistant Enterobacterales (3GCR-E), MRSA and VRE. Resistance percentage and mortality outcomes were reported as median (IQR) and crude mortality (%), respectively.

Results

Of 945 studies identified, 52 were included. Most were retrospective (41/52) and/or single centre (37/52), and liver transplantation was the most frequently studied SOT type (22/52). High resistance percentages of BSIs were noted, ranging from 13.6% CRE for Enterobacterales to 59.2% CRAB for A. baumannii. Resistance percentage trends decreased over time, but these changes were not statistically significant. Asia had the highest resistance percentages for MRSA [86.2% (IQR 77.3%-94.6%)], 3GCR-E [59.5% (IQR 40.5%-66.7%)] and CRE [35.7% (IQR 8.3%-63.1%)]. North America had the highest VRE resistance percentages [77.7% (IQR 54.6%-94.7%)]. Crude mortality was 15.4%-82.4% and was consistently higher than for non-MDRO BSIs.

Conclusions

MDRO BSI resistance percentages were high for all pathogens studied (IQR 24.6%-69.4%) but there was geographical and temporal heterogeneity. MDRO BSIs were associated with high mortality in SOT recipients. Microbiological and clinical data in this vulnerable population were incomplete, highlighting the need for robust international multicentre studies.

Septic shock in the immunocompromised cancer patient: a narrative review

Immunosuppressed patients, particularly those with cancer, represent a momentous and increasing portion of the population, especially as cancer incidence rises with population growth and aging. These patients are at a heightened risk of developing severe infections, including sepsis and septic shock, due to multiple immunologic defects such as neutropenia, lymphopenia, and T and B-cell impairment. The diverse and complex nature of these immunologic profiles, compounded by the concomitant use of immunosuppressive therapies (e.g., corticosteroids, cytotoxic drugs, and immunotherapy), superimposed by the breakage of natural protective barriers (e.g., mucosal damage, chronic indwelling catheters, and alterations of anatomical structures), increases the risk of various infections. These and other conditions that mimic sepsis pose substantial diagnostic and therapeutic challenges. Factors that elevate the risk of progression to septic shock in these patients include advanced age, pre-existing comorbidities, frailty, type of cancer, the severity of immunosuppression, hypoalbuminemia, hypophosphatemia, Gram-negative bacteremia, and type and timing of responses to initial treatment. The management of vulnerable cancer patients with sepsis or septic shock varies due to biased clinical practices that may result in delayed access to intensive care and worse outcomes. While septic shock is typically associated with poor outcomes in patients with malignancies, survival has significantly improved over time. Therefore, understanding and addressing the unique needs of cancer patients through a new paradigm, which includes the integration of innovative technologies into our healthcare system (e.g., wireless technologies, medical informatics, precision medicine), targeted management strategies, and robust clinical practices, including early identification and diagnosis, coupled with prompt admission to high-level care facilities that promote a multidisciplinary approach, is crucial for improving their prognosis and overall survival rates.

Pre-existing Immunocompromising Conditions and Outcomes of Acute COVID-19 Patients Admitted for Pediatric Intensive Care

BACKGROUND

We aimed to determine if pre-existing immunocompromising conditions (ICCs) were associated with the presentation or outcome of patients with acute coronavirus disease 2019 (COVID-19) admitted for pediatric intensive care.

METHODS

Fifty-five hospitals in 30 US states reported cases through the Overcoming COVID-19 public health surveillance registry. Patients <21 years admitted 12 March 2020-30 December 2021 to the pediatric intensive care unit (PICU) or high-acuity unit for acute COVID-19 were included.

RESULTS

Of 1274 patients, 105 (8.2%) had an ICC, including 33 (31.4%) hematologic malignancies, 24 (22.9%) primary immunodeficiencies and disorders of hematopoietic cells, 19 (18.1%) nonmalignant organ failure with solid-organ transplantation, 16 (15.2%) solid tumors, and 13 (12.4%) autoimmune disorders. Patients with ICCs were older, had more underlying renal conditions, and had lower white blood cell and platelet counts than those without ICCs, but had similar clinical disease severity upon admission. In-hospital mortality from COVID-19 was higher (11.4% vs 4.6%, P = .005) and hospitalization was longer (P = .01) in patients with ICCs. New major morbidities upon discharge were not different between those with and without ICC (10.5% vs 13.9%, P = .40). In patients with ICCs, bacterial coinfection was more common in those with life-threatening COVID-19.

CONCLUSIONS

In this national case series of patients <21 years of age with acute COVID-19 admitted for intensive care, existence of a prior ICCs were associated with worse clinical outcomes. Reassuringly, most patients with ICCs hospitalized in the PICU for severe acute COVID-19 survived and were discharged home without new severe morbidities.

Management of Immunosuppressive Therapy in Kidney Transplant Recipients with Sepsis: A Multicenter Retrospective Study

BACKGROUND

Up to 6% of kidney transplant recipients (KTRs) experience life-threatening complications requiring intensive care unit (ICU) admission, and one of the most common medical complications requiring ICU admission is infection. This study aimed to evaluate the effect of immunosuppressive therapy (IST) modification on prognosis of KTRs with sepsis.

METHODS

We conducted a multicenter retrospective study in 4 university-affiliated hospitals to evaluate the effect of adjusting the IST in KTRs with sepsis. Only patients who either maintained IST after ICU admission or those who underwent immediate (within 24 h of ICU admission) reduction or withdrawal of IST following ICU admission were included in this study. "Any reduction" was defined as a dosage reduction of any IST or discontinuation of at least 1 IST. "Complete withdrawal of IST" was defined as concomitant discontinuation of all ISTs, except steroids.

RESULTS

During the study period, 1596 of the KTRs were admitted to the ICU, and 112 episodes of sepsis or septic shock were identified. The overall in-hospital mortality rate was 35.7%. In-hospital mortality was associated with higher sequential organ failure assessment score, simplified acute physiology score 3, non-identical human leukocyte antigen relation, presence of septic shock, and complete withdrawal of IST. After adjusting for potential confounding factors, complete withdrawal of IST remained significantly associated with in-hospital mortality (adjusted coefficient, 1.029; 95% confidence interval, 0.024-2.035) and graft failure (adjusted coefficient, 2.001; 95% confidence interval, 0.961-3.058).

CONCLUSIONS

Complete IST withdrawal was common and associated with worse outcomes in critically ill KTRs with sepsis.

Preventive Antibiotic Use and Complications After Endoscopic Retrograde Cholangiopancreatography in Patients Hospitalized for Primary Sclerosing Cholangitis

BACKGROUND

The American Society for Gastrointestinal Endoscopy recommends prophylactic antibiotics before endoscopic retrograde cholangiopancreatography (ERCP) in primary sclerosing cholangitis (PSC). We assessed the impact of this approach on the incidence of post-ERCP outcomes using nationwide data.

METHODS

Using 2015-2021 Nationwide Inpatient Sample data and relevant ICD-10 codes, we analyzed adult hospitalizations for PSC who underwent ERCP, with and without antibiotic prophylaxis. Hierarchical multivariate logistic regression analysis was used to assess the association between prophylactic antibiotic use and post-ERCP complications including sepsis, acute cholangitis, and acute pancreatitis.

RESULTS

We analyzed 32,972 hospitalizations for PSC involving ERCP, with 12,891 admissions (39.1%) receiving antibiotics before ERCP (cases) and 20,081 (60.9%) serving as controls. Cases were older than controls (mean age: 64.2 ± 8.6 vs. 61.3 ± 6.1 years; P = 0.020). Compared with controls, hospitalizations with antibiotic prophylaxis had a higher male population (7,541 (58.5%) vs. 11,265 (56.1%); P < 0.001) and higher comorbidity burden (Charlson comorbidity index score of ≥2: 5,867 (45.5%) of cases vs. 8,996 (44.8%) of controls; P = 0.01). Incidence of post-ERCP septicemia was 19.1% (6,275) with 2,935 incidences (22.8%) among cases compared with 3,340 (16.6%) among controls. Antibiotic prophylaxis did not significantly improve the odds of septicemia (aOR: 0.85; 95% CI: 0.77 - 1.09; P = 0.179). Approximately 2,271 (6.9%) cases of acute cholangitis and 5,625 (17.1%) cases of acute post-ERCP pancreatitis were recorded. After adjustments for multiple variables, no significant difference was observed in the odds of cholangitis (aOR: 0.87; 95% CI: 0.98 - 1.45; P = 0.08). However, antibiotic prophylaxis was correlated with a statistically significant reduction in the odds ratio of acute post-ERCP pancreatitis (aOR: 0.61; 95% CI: 0.57 - 0.66; P < 0.001).

CONCLUSION

The use of antibiotic prophylaxis in hospitalizations with PSC was correlated with a significant reduction in the odds of post-ERCP pancreatitis. Antibiotic prophylaxis did not improve the odds of post-ERCP sepsis or cholangitis. Prophylactic use of antibiotics should be individualized, considering both their anti-infective benefits and potential impact on the biochemical markers of liver disease.

Physiologic disruption and metabolic reprogramming in infection and sepsis

Effective responses against severe systemic infection require coordination between two complementary defense strategies that minimize the negative impact of infection on the host: resistance, aimed at pathogen elimination, and disease tolerance, which limits tissue damage and preserves organ function. Resistance and disease tolerance mostly rely on divergent metabolic programs that may not operate simultaneously in time and space. Due to evolutionary reasons, the host initially prioritizes the elimination of the pathogen, leading to dominant resistance mechanisms at the potential expense of disease tolerance, which can contribute to organ failure. Here, we summarize our current understanding of the role of physiological perturbations resulting from infection in immune response dynamics and the metabolic program requirements associated with resistance and disease tolerance mechanisms. We then discuss how insight into the interplay of these mechanisms could inform future research aimed at improving sepsis outcomes and the potential for therapeutic interventions.

Basics and Art of Immunosuppression in Liver Transplantation

Liver transplantation is one of the most challenging areas in the medical field. Despite that, it has already been established as a standard treatment option, especially in decompensated cirrhosis and selected cases of hepatocellular carcinoma and acute liver failure. Complications due to graft rejection, including mortality and morbidity, have greatly improved over time due to better immunosuppressive agents and management protocols. Currently, immunosuppression in liver transplant patients makes use of the best possible combinations of effective agents to achieve optimal immunosuppression for long-term graft survival. Induction agents are no longer used routinely, and the aim is to provide minimal immunosuppression in the maintenance phase. Currently available immunosuppressive agents are mainly classified as biological and pharmacological agents. Though the protocols may vary among the centers and over time, the basics of effective use usually remain similar. Most protocols use the combination of multiple agents with different mechanisms of action to reduce the dose and minimize the side effects. Along with the improvement in operative and perioperative techniques, this art of immunosuppression has contributed to the recent progress made in the outcomes of liver transplants. In this review, we will discuss the various types of immunosuppressive agents currently in use, the different protocols of immunosuppression used, and the art of optimal use for achieving maximum immunosuppression without increasing toxicity. We will also discuss the practical aspects of various immunosuppression regimens, including drug monitoring, and briefly discuss the concepts of immunosuppression minimization and withdrawal.

Infections in Heart and Lung Transplant Recipients

Infections in heart and lung transplant recipients are complex and heterogeneous. This article reviews the epidemiology, risk factors, specific clinical syndromes, and most frequent opportunistic infections in heart and/or lung transplant recipients that will be encountered in the intensive care unit and will provide a practical approach of empirical management.

Low levels of small HDL particles predict but do not influence risk of sepsis

BACKGROUND

Low levels of high-density lipoprotein (HDL) cholesterol have been associated with higher rates and severity of infection. Alterations in inflammatory mediators and infection are associated with alterations in HDL cholesterol. It is unknown whether the association between HDL and infection is present for all particle sizes, and whether the observed associations are confounded by IL-6 signalling.

METHODS

In the UK Biobank, ~ 270,000 individuals have data on HDL subclasses derived from nuclear magnetic resonance analysis. We estimated the association of particle count of total HDL and HDL subclasses (small, medium, large, and extra-large HDL) with sepsis, sepsis-related death, and critical care admission in a Cox regression model. We subsequently utilised genetic data from UK Biobank and FinnGen to perform Mendelian randomisation (MR) of each HDL subclass and sepsis to test for a causal relationship. Finally, we explored the role of IL-6 signalling as a potential causal driver of changes in HDL subclasses.

RESULTS

In observational analyses, higher particle count of small HDL was associated with protection from sepsis (Hazard ratio, HR 0.80; 95% CI 0.74-0.86, p = 4 × 10-9 comparing Quartile 4, highest quartile of HDL to Quartile 1, lowest quartile of HDL), sepsis-related death (HR 0.80; 95% CI 0.74-0.86, p = 2 × 10-4), and critical care admission with sepsis (HR 0.72 95% CI 0.60-0.85, p = 2 × 10-4). Parallel associations with other HDL subclasses were likely driven by changes in the small HDL compartment. MR analyses did not strongly support causality of small HDL particle count on sepsis incidence (Odds ratio, OR 0.98; 95% CI 0.89-1.07, p = 0.6) or death (OR 0.94, 95% CI 0.75-1.17, p = 0.56), although the estimate on critical care admission with sepsis supported protection (OR 0.73, 95% CI 0.57-0.95, p = 0.02). Bidirectional MR analyses suggested that increased IL-6 signalling was associated with reductions in both small (beta on small HDL particle count - 0.16, 95% CI - 0.10 to - 0.21 per natural log change in SD-scaled CRP, p = 9 × 10-8).and total HDL particle count (beta - 0.13, 95% CI - 0.09 to - 0.17, p = 7 × 10-10), but that the reverse effect of HDL on IL-6 signalling was largely null.

CONCLUSIONS

Low number of small HDL particles are associated with increased hazard of sepsis, sepsis-related death, and sepsis-related critical care admission. However, genetic analyses did not strongly support this as causal. Instead, we demonstrate that increased IL-6 signalling, which is known to alter infection risk, could confound associations with reduced HDL particle count, and suggest this may explain part of the observed association between (small) HDL particle count and sepsis.

Long-term immunosuppressive treatment is not associated with worse outcome in patients hospitalized in the intensive care unit for septic shock: the PACIFIC study

BACKGROUND

Except in a few retrospective studies mainly including patients under chemotherapy, information regarding the impact of immunosuppressive therapy on the prognosis of patients admitted to the intensive care unit (ICU) for septic shock is scarce. Accordingly, the PACIFIC study aimed to asses if immunosuppressive therapy is associated with an increased mortality in patients admitted to the ICU for septic shock.

METHODS

This was a retrospective epidemiological multicentre study. Eight high enroller centres in septic shock randomised controlled trials (RCTs) participated in the study. Patients in the "exposed" group were selected from the screen failure logs of seven recent RCTs and excluded because of immunosuppressive treatment. The "non-exposed" patients were those included in the placebo arm of the same RCTs. A multivariate logistic regression model was used to estimate the risk of death.

RESULTS

Among the 433 patients enrolled, 103 were included in the "exposed" group and 330 in the "non-exposed" group. Reason for immunosuppressive therapy included organ transplantation (n = 45 [44%]) or systemic disease (n = 58 [56%]). ICU mortality rate was 24% in the "exposed" group and 25% in the "non-exposed" group (p = 0.9). Neither in univariate nor in multivariate analysis immunosuppressive therapy was associated with a higher ICU mortality (OR: 0.95; [95% CI 0.56-1.58]: p =  0.86 and 1.13 [95% CI 0.61-2.05]: p =  0.69, respectively) or 3-month mortality (OR: 1.13; [95% CI 0.69-1.82]: p =  0.62 and OR: 1.36 [95% CI 0.78-2.37]: p =  0.28, respectively).

CONCLUSIONS

In this study, long-term immunosuppressive therapy excluding chemotherapy was not associated with significantly higher or lower ICU and 3-month mortality in patients admitted to the ICU for septic shock.

A, Sivaprasadan S, S. S. Immunosuppression in Liver Transplant Recipients in the Setting of Sepsis

Management of immunosuppression (IS) in liver transplant recipients in the setting of sepsis is an open stage for debate. The age-long practice of reduction or complete cessation of IS during sepsis has been followed by most centres across the world, although, their exact strategies are highly heterogeneous. On the other hand, the emergence of striking new evidence suggesting that there is, in fact, decreased mortality with the continuation of IS in sepsis, has raised doubts about our previously conceived intuitive notion that IS portends increased risk in sepsis. The theory postulated is that IS agents, perhaps reverse the state of dysregulated immune response in sepsis to that of an iatrogenically modulated immune response, thus dimming the inflammatory cascade and preventing its deleterious effects. Of note, none of these studies reported exaggerated rejection-related complications. These contrasting outlooks have made it rather onerous to formulate an evidence-based recommendation for liver transplant recipients afflicted with sepsis. Inclusion of transplanted patients in randomised controlled trials of sepsis-related interventions seems to be the need of the hour.

Differentiating infection, colonisation, and sterile inflammation in critical illness: the emerging role of host-response profiling

Infection results when a pathogen produces host tissue damage and elicits an immune response. Critically ill patients experience immune activation secondary to both sterile and infectious insults, with overlapping clinical phenotypes and underlying immunological mechanisms. Patients also undergo a shift in microbiota with the emergence of pathogen-dominant microbiomes. Whilst the combination of inflammation and microbial shift has long challenged intensivists in the identification of true infection, the advent of highly sensitive molecular diagnostics has further confounded the diagnostic dilemma as the number of microbial detections increases. Given the key role of the host immune response in the development and definition of infection, profiling the host response offers the potential to help unravel the conundrum of distinguishing colonisation and sterile inflammation from true infection. This narrative review provides an overview of current approaches to distinguishing colonisation from infection using routinely available techniques and proposes matrices to support decision-making in this setting. In searching for new tools to better discriminate these states, the review turns to the understanding of the underlying pathobiology of the host response to infection. It then reviews the techniques available to assess this response in a clinically applicable context. It will cover techniques including profiling of transcriptome, protein expression, and immune functional assays, detailing the current state of knowledge in diagnostics along with the challenges and opportunities. The ultimate infection diagnostic tool will likely combine an assessment of both host immune response and sensitive pathogen detection to improve patient management and facilitate antimicrobial stewardship.

Sepsis affects kidney graft function and one-year mortality of the recipients in contrast with systemic inflammatory response

Background

Infections remain a major cause of morbidity and mortality after kidney transplantation. The aim of our study was to determine the effect of sepsis on kidney graft function and recipient mortality.

Methods

A prospective, observational, single-center study was performed. Selected clinical and biochemical parameters were recorded and compared between an experimental group (with sepsis, n = 34) and a control group (with systemic inflammatory response syndrome, n = 31) comprising kidney allograft recipients.

Results

Sepsis worsened both patient (HR = 14.77, p = 0.007) and graft survival (HR = 15.07, p = 0.007). Overall one-year mortality was associated with age (HR = 1.08, p = 0.048), APACHE II score (HR = 1.13, p = 0.035), and combination immunosuppression therapy (HR = 0.1, p = 0.006), while graft survival was associated with APACHE II (HR = 1.25, p = 0.004) and immunosuppression. In sepsis patients, mortality correlated with the maximal dose of noradrenalin (HR = 100.96, p = 0.008), fungal infection (HR = 5.64, p = 0.024), SAPS II score (HR = 1.06, p = 0.033), and mechanical ventilation (HR = 5.97, p = 0.033), while graft survival was influenced by renal replacement therapy (HR = 21.16, p = 0.005), APACHE II (HR = 1.19, p = 0.035), and duration of mechanical ventilation (HR = 1.01, p = 0.015).

Conclusion

In contrast with systemic inflammatory response syndrome, septic kidney allograft injury is associated with early graft loss and may represent a significant risk of mortality.

Patients with transplantation have reduced mortality in bacteraemia: Analysis of data from a randomised trial

OBJECTIVES

Infection remains a major complication of organ transplantation. Paradoxically, epidemiological studies suggest better survival from serious infection. We analysed the relationship between organ transplantation and short -term mortality of patients with bloodstream infection.

METHODS

Data on transplantation status was extracted from a large prospective, multi-centre clinical trial in bloodstream infection. Logistic regression for 28-day mortality was performed on the whole cohort and a propensity-matched cohort (3:1). Infective pathogen, focus of infection, and clinical variables were included in the model. Mediation analysis was performed on clinical variables to explore causation.

RESULTS

4,178 participants were included in the full cohort, with 868 in the matched cohort, of which 217 received an organ transplant. Haematopoietic stem cell transplants (HSCT) were the most common transplant (n = 99), followed by kidney (n = 70). The most common pathogens were staphylococci and Enterobacterales. Transplantation status was associated with a reduced mortality in both the whole (Odds Ratio, OR 0.53; 95% CI 0.28, 0.77) and matched (OR 0.55, 95% CI 0.34, 0.90) cohort, while steroid use was robustly associated with increased mortality OR 4.4 (95% CI 3.12, 6.20) in the whole cohort and OR 5.24 (95% CI 2.79, 9.84) in the matched cohort. There was no interaction between steroid use and transplant status, so transplant patients on steroids generally had increased mortality relative to those without either.

CONCLUSIONS

Organ transplantation is associated with a near halving of short term mortality in bloodstream infection, including a cohort matched for comorbidities, infective pathogen and focus. Steroid usage is associated with increased mortality regardless of transplant status. Understanding the mechanism and causation of this mortality benefit should be a focus of future research.

Acute kidney injury secondary to urinary tract infection in kidney transplant recipients

Acute kidney injury (AKI) in kidney transplant recipients (KTRs) is a common, yet poorly investigated, complication of urinary tract infections (UTI) and urosepsis. A retrospective comparative analysis was performed, recruiting 101 KTRs with urosepsis, 100 KTRs with UTI, and 100 KTRs without history of UTI or sepsis. The incidences of AKI in the urosepsis and UTI groups were 75.2% and 41%, respectively. The urosepsis group has also presented with a significantly higher prevalence of AKI stage 2 and 3 than the UTI group. The rates of recovery from AKI stages 1, 2 and 3, were 75,6%, 55% and 26.1%, respectively. Factors independently associated with renal recovery from AKI were: AKI severity grade (AKI stage 2 with OR = 0.25 and AKI stage 3 with OR = 0.1), transfusion of red blood cells (RBC) (OR = 0.22), and the use of steroid bolus in the acute phase of treatment (OR = 4). The septic status (urosepsis vs UTI) did not influence the rates of renal recovery from AKI after adjustment for the remaining variables. The dominant cause of RBC transfusions in the whole population was upper GI-bleeding. In multivariable analyses, the occurrence of AKI was also independently associated with a greater decline of eGFR at 1-year post-discharge and with a greater risk of graft loss. In KTRs with both urosepsis and UTI, the occurrence of AKI portends poor transplantation outcomes. The local transfusion policy, modulation of immunosuppression and stress ulcer prophylaxis (which is not routinely administered in KTRs) in the acute setting may be modifiable factors that significantly impact long-term transplantation outcomes.

The long-term impact of bloodstream infections on patient and graft survival following kidney transplantation

BACKGROUND

There are limited data on the impact of bloodstream infections (BSI) following kidney transplantation (KT) on long term patient outcome.

METHODS

This was a retrospective parallel-cohort study. We included 123 consecutive KT recipients who were admitted with a first episode of BSI between 1/2007-12/2016. They were matched with 225 KT recipients who did not have BSI. Multivariate regression analysis with BSI as time-dependent covariate was used for the effect of BSI on graft loss, all-cause mortality and long-term graft function (defined by the slope of mean serum creatinine level).

RESULTS

During a median follow-up of 89.4 months, post-transplant BSI was independently associated with all-cause mortality (HR 5.56, 95% CI 3.07-10.09, p<0.0001) and graft failure (HR-2.82, 95% CI 1.40-5.64, p = 0.003) after adjustment for potential confounders. This association remained irrespective of the source of infection or pathogen, but became non-significant when appropriate antibiotic therapy was administrated. Baseline kidney function was independently associated with graft failure. Recipients with BSI had lower baseline kidney function, however the BSI episode had no influence on the slope of change in serum creatinine over time.

CONCLUSION

BSI after KT was associated with long-term adverse outcome. This effect was mitigated by the early administration of appropriate antibiotics. This article is protected by copyright. All rights reserved.

Mortality in solid organ transplant recipients hospitalized for COVID-19

Kalil and Florescu discuss the growing evidence related to survival outcomes of solid organ transplant patients who are hospitalized due to COVID-19 and place this evidence within the context of other post-transplant infections. See Heldman et al. (page 279).

Changing Epidemiology and Decreased Mortality Associated With Carbapenem-resistant Gram-negative Bacteria, 2000-2017

BACKGROUND

Carbapenem-resistant gram-negative bacteria (CRGNB) continue to present a global healthcare crisis. We aimed to identify emerging trends of CRGNB over nearly 2 decades and describe the impact of CRGNB on patient outcomes.

METHODS

Patients from whom CRGNB were isolated between 2000 and 2017 were included in the study. Carbapenem resistance was defined by the most recent breakpoints and applied across the study period. Patient demographics, clinical characteristics, and outcomes were retrieved from the electronic health record.

RESULTS

A total of 94 888 isolates from 64 422 patients were identified; 9882 (10%) isolates from 4038 patients were carbapenem-resistant. Pseudomonas aeruginosa was the most common CRGNB each year. The second most common CRGNB emerged in waves over time. Carbapenem daily defined doses increased in parallel with CRGNB rates (R2 = 0.8131). The overall 30-day mortality rate was 19%, which decreased from 24% in 2000 to 17% in 2017 (P = .003; R2 = .4330). Among patients with CRGNB bloodstream infections (n = 319), overall 30- and 90-day mortality rates were 27% and 38%, respectively. Charlson score (adjusted odds ratio [aOR], 1.11 per point), intensive care unit residence (aOR, 7.32), and severe liver disease (aOR, 4.8.4) were independent predictors of 30-day mortality, while receipt of transplantation was associated with lower rates of death (aOR, 0.39). Among patients admitted between 2011 and 2017 (n = 2230), 17% died during hospitalization, 32% were transferred to long-term care facilities, and 38% were discharged home.

CONCLUSIONS

CRGNB emerged in waves over time, causing high rates of mortality. Despite increasing rates of CRGNB, overall patient outcomes have improved, suggesting that recognition and novel therapeutics have made a major impact.

Artificial Intelligence May Predict Early Sepsis After Liver Transplantation

Background: Sepsis, post-liver transplantation, is a frequent challenge that impacts patient outcomes. We aimed to develop an artificial intelligence method to predict the onset of post-operative sepsis earlier. Methods: This pilot study aimed to identify "physiomarkers" in continuous minute-by-minute physiologic data streams, such as heart rate, respiratory rate, oxygen saturation (SpO2), and blood pressure, to predict the onset of sepsis. The model was derived from a cohort of 5,748 transplant and non-transplant patients across intensive care units (ICUs) over 36 months, with 92 post-liver transplant patients who developed sepsis. Results: Using an alert timestamp generated with the Third International Consensus Definition of Sepsis (Sepsis-3) definition as a reference point, we studied up to 24 h of continuous physiologic data prior to the event, totaling to 8.35 million data points. One hundred fifty-five features were generated using signal processing and statistical methods. Feature selection identified 52 highly ranked features, many of which included blood pressures. An eXtreme Gradient Boost (XGB) classifier was then trained on the ranked features by 5-fold cross validation on all patients (n = 5,748). We identified that the average sensitivity, specificity, positive predictive value (PPV), and area under the receiver-operator curve (AUC) of the model after 100 iterations was 0.94 ± 0.02, 0.9 ± 0.02, 0.89 ± 0.01, respectively, and 0.97 ± 0.01 for predicting sepsis 12 h before meeting criteria. Conclusion: The data suggest that machine learning/deep learning can be applied to continuous streaming data in the transplant ICU to monitor patients and possibly predict sepsis.

Survival Outcome of Sepsis in Recipients of Solid Organ Transplant

Sepsis is a complex disease stemming from a dysregulated immune response toward an infectious agent. In transplantation, sepsis remains one of the leading causes of morbidity and mortality. Solid organ transplant recipients have impaired adaptive immunity due to immunosuppression required to prevent rejection. Immunosuppression has unintended consequences, such as increasing the risk of infections and sepsis. Due to its high morbidity and mortality, early detection of sepsis is paramount to start aggressive treatment. Several biomarkers or combination of biomarkers of sepsis have emerged in the last decade, but they are not dependable for early diagnosis or for outcome prognosis.

Vasoplegia from Continuous Flow Left Ventricular Assist Devices

PURPOSE OF REVIEW

The contribution of continuous flow left ventricular assist devices (c-LVAD) to vasoplegic syndrome and postoperative outcomes after orthotopic heart transplant (OHT) is contested in the literature. A standardized definition of vasoplegic syndrome (VS) is needed to better recognize and manage vasoplegic shock.

RECENT FINDINGS

Vasoplegic syndrome occurs after orthotopic heart transplant more frequently than after other surgeries requiring cardiopulmonary bypass. c-LVADs lead to small vessel endothelial dysfunction and desensitized adrenal receptors; however, their contribution to the development of vasoplegia is debated in clinical studies. Pulsatility may mitigate vascular dysfunction resulting from long-term continuous flow, and should be further explored in the clinical setting when considering risk factors for vasoplegic syndrome. The incidence of vasoplegic syndrome after orthotopic heart transplant is rising with the increasing use of c-LVAD bridge to therapy. Robust clinical studies are needed to advance our understanding and approach to mitigating VS after OHT.

Pre-transplant T-cell Clonality: An Observational Study of a Biomarker for Prediction of Sepsis in Liver Transplant Recipients

OBJECTIVE

This study investigated the ability of pre-transplant T-cell clonality to predict sepsis after liver transplant (LT).

SUMMARY BACKGROUND DATA

Sepsis is a leading cause of death in LT recipients. Currently, no biomarkers predict sepsis before clinical symptom manifestation.

METHODS

Between December 2013 and March 2018, our institution performed 478 LTs. After exclusions (eg, patients with marginal donor livers, autoimmune disorders, nonabdominal multi-organ, and liver retransplantations), 180 consecutive LT were enrolled. T-cell characterization was assessed within 48 hours before LT (immunoSEQ Assay, Adaptive Biotechnologies, Seattle, WA). Sepsis-2 and Sepsis-3 cases, defined by presence of acute infection plus ≥2 SIRS criteria, or clinical documentation of sepsis, were identified by chart review. Receiver-operating characteristic analyses determined optimal T-cell repertoire clonality for predicting post-LT sepsis. Kaplan-Meier and Cox proportional hazard modeling assessed outcome-associated prognostic variables.

RESULTS

Patients with baseline T-cell repertoire clonality ≥0.072 were 3.82 (1.25, 11.40; P = 0.02), and 2.40 (1.00, 5.75; P = 0.049) times more likely to develop sepsis 3 and 12 months post-LT, respectively, when compared to recipients with lower (<0.072) clonality. T-cell repertoire clonality was the only predictor of sepsis 3 months post-LT in multivariate analysis (C-Statistic, 0.75). Adequate treatment resulted in equivalent survival rates between both groups: (93.4% vs 96.2%, respectively, P = 0.41) at 12 months post-LT.

CONCLUSIONS

T-cell repertoire clonality is a novel biomarker predictor of sepsis before development of clinical symptoms. Early sepsis monitoring and management may reduce post-LT mortality. These findings have implications for developing sepsis-prevention protocols in transplantation and potentially other populations.

Coronavirus Disease 2019 in Kidney Transplant Recipients: Single-Center Experience and Case-Control Study

BACKGROUND

Kidney transplant recipients (KTR) are considered high-risk for morbidity and mortality from coronavirus disease 2019 (COVID-19). However, some studies did not show worse outcomes compared to non-transplant patients and there is little data about immunosuppressant drug levels and secondary infections in KTR with COVID-19. Herein, we describe our single-center experience with COVID-19 in KTR.

METHODS

We captured KTR diagnosed with COVID-19 between March 1, 2020 and May 18, 2020. After exclusion of KTR on hemodialysis and off immunosuppression, we compared the clinical course of COVID-19 between hospitalized KTR and non-transplant patients, matched by age and sex (controls).

RESULTS

Eleven KTR were hospitalized and matched with 44 controls. One KTR and 4 controls died (case fatality rate: 9.1%). There were no significant differences in length of stay or clinical outcomes between KTR and controls. Tacrolimus or sirolimus levels were >10 ng/mL in 6 out of 9 KTR (67%). Bacterial infections were more frequent in KTR (36.3%), compared with controls (6.8%, P = .02).

CONCLUSIONS

In our small case series, unlike earlier reports from the pandemic epicenters, the clinical outcomes of KTR with COVID-19 were comparable to those of non-transplant patients. Calcineurin or mammalian target of rapamycin inhibitor (mTOR) levels were high. Bacterial infections were more common in KTR, compared with controls.

Sepsis in Immunocompromised Patients Without Human Immunodeficiency Virus

Sepsis remains among the most common complications from infectious diseases worldwide. The morbidity and mortality rates associated with sepsis range from 20% to 50%. The advances in care for patients with an immunocompromised status have been remarkable over the last 2 decades, but sepsis continues to be a major cause of death in this population Immunocompromised patients who are recipients of a solid organ or hematopoietic stem cell transplant are living longer with a better quality of life. However, some of these patients need lifelong treatment with immunosuppressive medications to maintain their transplant status. A consequence of the need for this permanent immunosuppression is the high risk of opportunistic, community, and hospital-acquired infections, all of which can lead to sepsis. In addition, the detection of serious infections may be more challenging owing to patients' lower ability to mount the clinical symptoms that usually accompany sepsis. This article provides an update on the current knowledge of sepsis in immunocompromised patients without human immunodeficiency virus. It reviews the most pertinent causes of sepsis in this population, and addresses the specific diagnostic and therapeutic challenges in neutropenia and solid organ and hematopoietic stem cell transplantation.

SARS-CoV-2 infection in kidney transplant recipients: Early report of five cases

From December 2019 to March 2020, China was the epicenter of the SARS‐CoV‐2 infection pandemic, but from that moment on, Europe surpassed China in the number of new cases and deaths related to this novel viral respiratory infection. The emergence of this world pandemic is particularly important for solid organ transplant recipients, who might have an increased risk of mortality, not only due to their chronic immunosuppression status, but also to the cardiovascular risk that correlates with several years of chronic kidney disease. To the extent that there is still a lack of knowledge about the clinical characteristics, evolution, and prognosis of SARS‐CoV‐2 infection in kidney transplant recipients, we will report the first 5 cases diagnosed and followed in our transplant unit, as well as share the therapeutic strategies adopted.

Sepsis outcomes in solid organ transplant recipients

BACKGROUND

We present data on a cohort of patients diagnosed with sepsis over a 10-year period comparing outcomes in solid organ transplant (SOT) and non-solid organ transplant (non-SOT) recipients.

METHODS

This is a retrospective single-center study of patients with diagnosis of sepsis from 1/1/06 to 6/30/16. Cases and controls were matched by year of sepsis diagnosis with propensity score matching. Conditional logistic regression and repeated measurement models were performed for binary outcomes. Trends over time for in-hospital mortality were determined using the Cochran-Armitage test. A gamma-distributed model was performed on the continuous variables.

RESULTS

Overall, there were 18 632 admission encounters with a discharge diagnosis of sepsis in 14 780 unique patients. Of those admissions, 1689 were SOT recipients. After 1:1 matching by year, there were three thousand three hundred and forty patients (1670 cases; 1670 controls) diagnosed with sepsis. There was a decreasing trend for in-hospital mortality for sepsis over time in SOT patients and non-SOT patients (P < .05) due to early sepsis recognition and improved standard of care. Despite higher comorbidities in the SOT group, conditional logistic regression showed that in-hospital mortality for sepsis in SOT patients was similar compared with non-SOT patients (odds ratio [OR] =1.14 [95% confidence interval {CI}, 0.95-1.37], P = .161). However, heart and lung SOT subgroups had higher odds of dying compared with the non-SOT group (OR = 1.83 [95% CI, 1.30-2.57], P < .001 and OR = 1.77 [95% CI, 1.34-2.34], P < .001). On average, SOT patients had 2 days longer hospital length of stay compared with non-SOT admissions (17.00 ± 19.54 vs 15.23 ± 17.07, P < .05). Additionally, SOT patients had higher odds of hospital readmission within 30 days (OR = 1.25 [95% CI, 1.06-1.51], P = .020), and higher odds for DIC compared with non-SOT patients (OR = 1.76 [95% CI, 1.10-2.86], P = .021).

CONCLUSION

Sepsis in solid organ transplants and non-solid organ transplant patients have similar mortality; however, the subset of heart and lung transplant recipients with sepsis has a higher rate of mortality compared with the non-solid organ transplant recipients. SOT with sepsis as a group has a higher hospital readmission rate compared with non-transplant sepsis patients.

Immunosuppression reduction in kidney transplant recipients during bacterial infection-A retrospective study

BACKGROUND

Immunosuppression reduction is a common practice in the management of bacterial infection among kidney transplant recipients (KTRs). This practice, however, is based on limited evidence.

METHODS

Retrospective study comparing clinical outcomes of KTRs whose antimetabolite was discontinued vs continued during hospitalization due to bacterial infection, considering calcineurin inhibitors (CNI) levels. Primary outcome was a composite of clinical failure at day 5; all-cause mortality; and/or re-hospitalization at 90 days. Multivariable analysis of risk factors for the primary outcome was performed using a propensity-matched cohort.

RESULTS

We included 183 KTRs hospitalized with bacterial infection. Neither discontinuation of antimetabolites nor lower levels of CNI at infection onset were associated with a significant decrease the composite primary outcome. No significant difference in graft loss or rejection was demonstrated between patients with low vs high CNI levels or discontinuation vs continuation of antimetabolite. In multivariable analysis, CNI levels and management of antimetabolite were not significantly associated with adverse outcome.

CONCLUSIONS

Immunosuppression reduction in hospitalized KTRs with bacterial infection did not offer a clinical advantage in terms of mortality, re-hospitalization, or clinical success. An interventional study evaluating continuation of immunosuppression vs reduction should be considered.

Immunosuppression reduction in liver and kidney transplant recipients with suspected bacterial infection: A multinational survey

BACKGROUND

There is no consensus on the optimal management of immunosuppression during bacterial infections among solid organ transplant recipients.

METHODS

A multicenter, cross-sectional survey, of high-volume kidney and liver transplant centers across US and Europe. Structured questionnaires including six multiple-choice questions concerning the management of immunosuppression during infection were distributed among 381 centers.

RESULTS

A total of 124 (33%) centers fully completed the questionnaire: 67 liver, 57 kidney centers. Participating centers reported heterogenous approaches to immunosuppression management for all types of immunosuppressive drugs. Notably, kidney centers reported similar frequencies of either discontinuation (19%), continuation (19%), or dose reduction (17.5%) of antimetabolites; discontinuation only for life-threatening infection (17.5%) or case by case decisions (27%). Calcineurin inhibitors (CNI) management was heterogenous mostly among liver centers, with 8% discontinuing the CNI, 18% continuing, and 22% reducing dose. Heterogenous approaches to management of steroids and inhibitors of the mammalian target of rapamycin were also demonstrated.

CONCLUSIONS

Immunosuppression management during bacterial infection is heterogenous in US and European centers. Immunosupression reduction (ISR) during infection is a common practice, though supported by limited evidence. Demonstrating high heterogeneity in the approach to ISR, together with the equivocal results of clinical studies, support consideration of an interventional clinical trial.

Clinical and economic burden of infections in hospitalized solid organ transplant recipients compared with the general population in Canada - a retrospective cohort study

Infections continue to be a major cause of post-transplant morbidity and mortality, requiring increased health services utilization. Estimates on the magnitude of this impact are relatively unknown. Using national administrative databases, we compared mortality, acute care health services utilization, and costs in solid organ transplant (SOT) recipients to nontransplant patients using a retrospective cohort of hospitalizations in Canada (excluding Manitoba/Quebec) between April-2009 and March-2014, with a diagnosis of pneumonia, urinary tract infection (UTI), or sepsis. Costs were analyzed using multivariable linear regression. We examined 816 324 admissions in total: 408 352 pneumonia; 328 066 UTI's; and 128 275 sepsis. Unadjusted mean costs were greater in SOT compared to non-SOT patients with pneumonia [(C$14 923 ± C$29 147) vs. (C$11 274 ± C$18 284)] and sepsis [(C$23 434 ± C$39 685) vs. (C$20 849 ± C$36 257)]. Mortality (7.6% vs. 12.5%; P < 0.001), long-term care transfer (5.3% vs. 16.5%; P < 0.001), and mean length of stay (11.0 ± 17.7 days vs. 13.1 ± 24.9 days; P < 0.001) were lower in SOT. More SOT patients could be discharged home (63.2% vs. 44.3%; P < 0.001), but required more specialized care (23.5% vs. 16.1%; P < 0.001). Adjusting for age and comorbidities, hospitalization costs for SOT patients were 10% (95% CI: 8-12%) lower compared to non-SOT patients. Increased absolute hospitalization costs for these infections are tempered by lower adjusted costs and favorable clinical outcomes.

Carbapenem-Resistant Enterobacteriaceae in Solid Organ Transplantation: Management Principles

PURPOSE OF REVIEW

Carbapenem-resistant Enterobacteriaceae (CRE) have emerged as a worldwide problem. Given their degree of immunosuppression and the level of contact with the healthcare system, solid organ transplant (SOT) recipients are at a disproportionately higher risk of acquisition, colonization, and infection with CRE, and outcomes from infection tend to be worse compared to non-transplant patients. Therapeutic options are limited for CRE infections although several newer agents have recently been approved for use. How well these agents perform in the setting of immunosuppression and SOT is unclear. We sought to review the epidemiology of CRE in SOT and the management principles.

RECENT FINDINGS

CRE infections are becoming an increasing problem in SOT, and donor-derived infections present a challenge in the peri-transplant period. Newer treatments for CRE are emerging that are less toxic and potentially more effective than prior CRE-active agents, but supportive clinical data are limited. Newer beta-lactamase inhibitors have good activity against KPC carbapenemases, but they lack activity against metallo-beta-lactamases (e.g., NDM). Promising data is emerging with newer agents that have activity against most carbapenemases, but, again, clinical data is needed. Combination therapy in addition to optimal pharmacokinetic and pharmacodynamics may go some way to improve outcomes against these difficult-to-treat organisms. Other novel therapies that prevent the emergence of resistance (oral beta-lactamase inhibitors) and eradication of resistant Gram-negative colonization (fecal microbiota transplant) may eventually become part of a bundle approach to reduce CRE infections in the future. As in non-transplant patients, CRE infections in the transplant setting are challenging to treat and prevent. Infection prevention and control remains crucial to prevent widespread dissemination, and unique challenges exist with donor-derived CRE and how best to manage recipients in the peri-transplant period. Newer treatments are now in early-phase clinical studies, and in vitro activity data are supportive for several agents providing hope for improved outcomes with these typically difficult-to-treat and highly morbid infections in transplant recipients.

Prise en charge du transplanté rénal en réanimation

La transplantation rénale est la thérapeutique de choix de l’insuffisance rénale chronique au stade ultime, son usage est de plus en plus large. Les progrès réalisés dans les traitements immunosuppresseurs ont permis une amélioration de la durée de vie du greffon, mais au prix d’une augmentation des complications cardiovasculaires et infectieuses. Environ 5 % des transplantés rénaux présentent des complications sévères qui nécessitent une prise en charge intensive. Elles sont principalement de cause infectieuse et dominées par la défaillance respiratoire aiguë. L’insuffisance rénale aiguë est commune, elle affecte la fonction du greffon à court et long termes. La prise en charge en réanimation de ces complications doit prendre en compte le terrain particulier du transplanté rénal et les effets délétères de l’immunosuppression, condition nécessaire à une amélioration de la mortalité qui reste à plus de 30 %.

Infections in Heart and Lung Transplant Recipients

Infections in heart and lung transplant recipients are complex and heterogeneous. This article reviews the epidemiology, risk factors, specific clinical syndromes, and most frequent opportunistic infections in heart and/or lung transplant recipients that will be encountered in the intensive care unit and will provide a practical approach of empirical management.

Risk Factors for Sepsis Based on Sepsis-3 Criteria after Orthotopic Liver Transplantation

Sepsis is a common complication of solid organ transplant procedures and, in particular, can affect the prognosis of orthotopic liver transplantation (OLT). This retrospective study determined the pre-, peri-, and postoperative risk factors for sepsis after OLT, using as reference the 2016 Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3). Pre-, peri-, and postoperative clinical data of the sepsis-positive (n = 85) and sepsis-negative (n = 41) groups were analyzed for potential risk factors of OLT-related sepsis. The sepsis-positive patients had a significantly higher rate of dialysis (49.4%), longer time under mechanical ventilation (1.5 d), higher hospitalization costs (0.41 million RMB), and worse survival rate (68.5%), compared with the sepsis-negative patients (4.8%, 1 d, 0.30 million RMB, and 73.1%, resp.). The multivariate logistic analysis identified the following as risk factors for OLT-related sepsis: preoperative Child-Pugh grade C (OR 10.43; 95% CI 2.081–52.292; P = 0.004), preoperative hypercalcemia (OR 6.372; 95% CI 1.693–23.98; P = 0.006), and perioperative acidosis (OR 6.364; 95% CI 1.196–33.869; P = 0.030). Patients with preoperative Child-Pugh grade C, preoperative hypercalcemia, or perioperative acidosis are at higher risk for developing sepsis after OLT. When any of these problems occur, timely sepsis management should be planned.

Management of immunosuppressive therapy in liver transplant recipients who develop bloodstream infection

BACKGROUND

Data about the optimal management of immunosuppressive therapy in liver transplant (LT) recipients with bloodstream infection (BSI) are missing. We aimed to describe the management of immunosuppressive therapy at diagnosis of BSI in LT recipients and to assess its impact on 28-day mortality.

METHODS

We performed a single-center retrospective study of all LT recipients diagnosed with BSI, over 10-year period. Multivariate Cox regression analysis of risk factors for all cause 28-day mortality was adjusted for the propensity score of being managed with "any reduction" in immunosuppressive therapy at the diagnosis of BSI.

RESULTS

We identified 209 episodes of BSI in 157 LT recipients: 107 (68%) male, median age 54 (IQR 48-63) years. "Any reduction" was made in 90 (43%) cases including: dosage reduction of ≥1 immunosuppressive drug in 31 (15%), discontinuation of ≥1 immunosuppressive drug in 28 (13%), both dosage reduction and discontinuation in 13 (6%), complete withdrawal of immunosuppressive therapy in 18 (9%) cases. All-cause 28-day mortality rate was 13.4%, varying from 22% to 7% (P = .002) in cases with and without "any reduction". Cox regression showed septic shock (aHR 3.15, P = .007) and "any reduction" (aHR 2.50, P = .02) as independent risk factors for all-cause 28-day mortality, while Escherichia coli (aHR 0.38, P = .03) and source control (aHR 0.43, P = .04) were protective factors. The final model did not change after the introduction of the propensity score for "any reduction".

CONCLUSIONS

Any reduction in the immunosuppressive therapy was common and was associated with worse outcome in LT recipients developing BSI.

Severe infections in critically ill solid organ transplant recipients

BACKGROUND

Severe infections are among the most common causes of death in immunocompromised patients admitted to the intensive care unit. The epidemiology, diagnosis and treatment of these infections has evolved in the last decade.

AIMS

We aim to provide a comprehensive review of these severe infections in this population.

SOURCES

Review of the literature pertaining to severe infections in critically ill solid organ transplant recipients. PubMed and Embase databases were searched for documents published since database inception until November 2017.

CONTENT

The epidemiology of severe infections has changed in the immunocompromised patients. This population is presenting to the intensive care unit with specific transplantation procedure-related infections, device-associated infections, a multitude of opportunistic viral infections, an increasing number of nosocomial infections and bacterial diseases with a more limited therapeutic armamentarium. Both molecular diagnostics and imaging techniques have had substantial progress in the last decade, which will, we hope, translate into faster and more precise diagnoses, as well as more optimal empirical treatment de-escalation.

IMPLICATIONS

The key clinical elements to improve the outcome of critically ill solid organ transplant recipients depend on the knowledge of geographic epidemiology, specific surgical procedures, net state of immunosuppression, hospital microbial ecology, aggressive diagnostic strategy and search for source control, rapid initiation of antimicrobials and minimization of iatrogenic immunosuppression.

Factors and outcomes in association with sepsis differ between simultaneous pancreas/kidney and single kidney transplant recipients

BACKGROUND

As immunosuppressive therapy has improved in simultaneous pancreas/kidney transplant recipients (SPKTRs), infection has become the major limitation of disease-free survival.

METHODS

We studied all SPKTRs and deceased-donor kidney transplant recipients (KTRs) between 2003 and 2015. Thirty-six of 134 SPKTRs (26.9%) were diagnosed with sepsis among which 13/36 SPKTRs (36.1%) developed severe sepsis/septic shock. A control group of 98 SPKTRs without sepsis and 61/538 KTRs (11.3%) with sepsis were used for comparison.

RESULTS

Among SPKTRs, female sex, low BMI, CMV seronegativity, CMV disease, and acute cellular rejection increased the risk for sepsis (P < .05). Patient and allograft survival was comparable among SPKTRs with and without sepsis (P > .05), but showed inferior kidney allograft function (P < .05). While urosepsis was less common among SPKTRs (45%), pneumonia (33%) and peritonitis (15%) as site of infections were more frequent (P < .05). Here, gram-positive and fungal sepsis were more common among SPKTRs compared to KTRs (P < .05). SPKTRs showed a higher incidence and an earlier onset of sepsis compared to KTRs (P < .001). SPKTRs with severe sepsis/septic shock were more likely to show pneumonia as site of infection with gram-positive/polymicrobial bacteremia (P < .05). Mortality from severe sepsis was 29% among SPKTRs compared to 58% among KTRs (P < .05).

CONCLUSION

Differences in incidence, site, causative pathogens, and onset of sepsis between SPKTRs and KTRs may be attributed to more intense immunosuppression, major surgery, and complications of diabetes among SPKTRs. Lower sepsis-related mortality may reflect younger age and more timely diagnosis, but also supports recent findings of less sepsis-related mortality among recipients of solid organ transplantation.

Changing trends in the aetiology, treatment and outcomes of bloodstream infection occurring in the first year after solid organ transplantation: a single-centre prospective cohort study

To analyse trends in the aetiology, treatment and outcomes of bloodstream infection (BSI) within the first year post-transplant over the last 10-year period, we prospectively recorded all episodes of BSI occurring in solid organ transplant (SOT) recipients during the first year post-transplant from 2007 to 2016. Trends of factors were analysed by 2-year periods. Of 475 consecutive episodes of BSI, 218 occurred within a year of SOT in 178 SOT recipients. Gram-positive BSI decreased over time (40.5-2.2%). In contrast, there was a steady increase in Gram-negative bacilli (GNB) BSI (54.1-93.3%; P < 0.001), mainly due to Pseudomonas aeruginosa (2.4-20.4%) and Klebsiella pneumoniae (7.1-26.5%). Multidrug-resistant (MDR) GNB (4.8-38.8%; P < 0.001) rose dramatically, especially due to extended-spectrum β-lactamase (ESBL) production (7.1-34.7%). There was a sharp rise in the use of carbapenems, both as empirical (11.9-55.3%; P < 0.001) and as targeted antibiotic treatment (11.9-46.9%; P < 0.001). In conclusion, today, GNB are the leading causative agents of BSI in SOT recipients within the first year after SOT. In addition, MDR GNB have emerged mainly due to ESBL-producing strains. In spite of these changes, length of hospital stay, days of treatment and mortality have remained stable over time.